The art field with respect to T-handle lock assemblies is fairly well known. T-handle lock assemblies of this type are commonly used in high security environments, which typically include coin changers, soft drink or food vending machines, mass transit collection systems, outdoor storage facilities, and similar applications. The intended purpose of such high security lock is to prevent unauthorized access to the contents of the related equipment, and prevent theft.
Generally, the pop-out T-handle lock assemblies operate by providing an external handle housing which covers the handle assembly when the cylinder front handle is depressed and lockingly engaged within the confines of the handle housing. In order to operate the lock, the key is inserted in the front key way, and manipulated in order to release the lock bolt which causes the entire handle assembly to pop forward due to the action of a coil spring which forces the entire pop-out handle outwardly. A lock device may then be operated because the extension rod has a screw threaded rear end, and the handle may then be moved in a counter clockwise direction to unscrew the threaded extension rod from the threaded channel in the rear. The locking procedure is simply reversed, with the handle being moved in a clockwise direction to screw threadingly engage the screw threaded extension rod in the threaded channel which is set within the confines of the box to be protected, and when the screw threading engagement has been achieved, the front handle is depressed into the handle housing until the lock bolt engages in the housing channel. In this position, access to the lock from unauthorized sources is prevented.
The prior art has made various attempts at making these types of locks more secure since many improvements have been met with counter systems or procedures to circumvent the improvements. In addition, while some of the improvements have been successful in preventing unauthorized access, some of such improvements have also rendered the servicing of the lock assemblies difficult if not impossible.
Typical prior art attempts at improving the security of the pop-out T-handle assemblies is illustrated in U.S. Pat. No. 4,552,001 which describes in great detail the improvements in such types of lock assemblies, and further illustrates a number of other prior art patents dealing with typical pop-out T-handle assemblies. However, the pop-out T-handle assembly as disclosed in U.S. Pat. No. 4,552,001, as well as those disclosed and claimed in the related patents as set forth therein, pose a serious problem for the service industry, at least as to those persons charged with the responsibility of servicing the locks once they are in place in the field.
More specifically, it will be noted that in order to remove the cylinder housing which contains the cylinder lock and related extension rod from the device for servicing purposes, not only must the pop-out handle be activated to biasingly pop outwardly, but the cylinder front handle must be removed from the housing in order to remove the cylinder lock from the cylinder housing. In order to accomplish that function, and with reference to U.S. Pat. No. 4,522,001, it will be noted that a pair of pins denoted by the numeral 28, must be removed from the cylinder front handle in order to remove the front handle to gain access to the lock. Such servicing problems exist where, for example, the user of the machine has broken a key in the lock, or for some reason, the lock has misfunctioned. In such cases, the entire cylinder lock must be replaced in order to make the T-handle lock assembly operational once again. It has been found by servicing personnel that the difficulty of removing the driven pins from the handle has rendered such lock assemblies almost unserviceable. It will be appreciated that in order to remove driven pins from the apertures in the cylinder front handle, the service personnel must apply a thin tool against one end of the pin, and literally drive the pin out of engagement by means of a mallet or hammer. However, it will be appreciated that such pop-out handles are designed to freely rotate, and hence, it is almost impossible to strike the pins with a mallet to remove the same without causing the handle to rotate. Hence, it has been found to be difficult if not in some cases impossible to remove such pins for servicing purposes.
The purpose of the present invention is to provide an improvement in such pop-out lock assemblies such that the servicing problems attendant to such high security locks is greatly enhanced.